isofs: fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
by explicitly adding a break statement instead of just letting the code
fall through to the next case.

Link: https://github.com/KSPP/linux/issues/115
Link: https://lkml.kernel.org/r/5b7caa73958588065fabc59032c340179b409ef5.1605896059.git.gustavoars@kernel.orgSigned-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/isofs/rock.c

@@ -767,6 +767,7 @@ static int rock_ridge_symlink_readpage(struct file *file, struct page *page)
 			rs.cont_extent = isonum_733(rr->u.CE.extent);
 			rs.cont_offset = isonum_733(rr->u.CE.offset);
 			rs.cont_size = isonum_733(rr->u.CE.size);
+			break;
 		default:
 			break;
 		}